Unlike tobacco, alcohol, and all other drugs of abuse, marijuana and its related cannabinoids make up the only class of drugs of which use is on the rise. Despite this trend, surprisingly few treatment options exist for the growing number of individuals who desire to quit. Common drug treatment approaches such as behavioral therapy are costly and have yielded modest success rates among marijuana users. A low cost, accessible treatment option for these individuals may be exercise. In the animal and human literature, exercise has been shown to decrease craving, lessen withdrawal, promote abstinence, and reduce reinstatement in a variety of drugs. However, no studies have explicitly examined the effects of exercise among treatment?seeking marijuana users. Thus, the overall objective of the proposed research is to examine whether exercise in conjunction with treatment?as?usual (TAU) is more effective than standard treatment in decreasing cravings, decreasing drug usage, and increasing abstinence among marijuana users. In addition, exercise is known to activate the endocannabinoid (eCB) system, which is the same physiological system affected by marijuana. The proposed study will not only extend the knowledge of exercise interventions in treatment?seeking cannabis users, but it will also be the first to investigate the eCBs as a mechanism contributing to treatment outcomes. A total of 28 males and females with a DSM?IV?TR diagnosis of cannabis abuse or dependency between the ages of 18?55yrs will engage in 6 weeks of either treatment?as?usual (TAU) at a local, outpatient counseling center OR TAU with exercise (EX). Throughout the trial, participants will be assessed on their marijuana usage, cravings, and physical/psychological symptoms of both drug abstinence and EX/TAU treatment. Moreover, participants will provide urine, salivary, and blood samples to assess changes in THC metabolites, cortisol, and eCBs over the 6 week period. Exploring a mechanistically?viable, accessible and affordable treatment option for marijuana users, such as exercise, will potentially be very important as marijuana use and the use of its more powerful synthetic derivatives continues to rise.